This invention generally pertains to a core sampling apparatus. More specifically, the present invention relates to an apparatus adapted for tissue biopsies in living creatures.
The invention is particularly applicable to a device for withdrawing a core of bone from the femur of a patient in a surgical technique for decompression of the femoral head in osteonecrosis. However, it will be appreciated by those skilled in the art that the invention has broader applications and may be useful in obtaining tissue biopsies in human beings or other creatures. Moreover, the invention has still broader applications and may also be adapted for the withdrawal of core samples from various non-living objects or structures.
Osteonecrosis, i.e. bone death, especially of a "head" section of the femur, i.e. the bone situated between the pelvis and the knee in humans, can lead to severe functional disability and immobility. Usually, such osteonecrosis necessitates a replacement of the hip joint with an artificial hip. It is estimated that between 110,000 and 120,000 such hip replacement operations are performed in the United States each year.
Although numerous etiologies have been associated with the development of osteonecrosis, one common cause of the disease involves increased intraosseous pressure in the femoral head. A decompression of the femoral head can be achieved by a removal of a core section of the bone in femoral head, this is called core decompression. Removal of such a core section usually will improve blood circulation around the femoral head and will also reduce pain.
Present biopsy instruments have not, however, been found suitable for the accomplishment of such core decompression. Most biopsy needles are only adapted for cutting soft tissue such as skin, muscle, kidney, liver, etc. Even those biopsy instruments which are adapted for obtaining bone samples are not designed in such a way as to be able to quickly and safely remove a core of bone while preserving the architecture or orientation of tissue and cell types within the core for biopsy purposes while at the same time not mutilating the remaining bone in the femur or the tissue lying between the skin and the femur.
Accordingly, it has been considered desirable to develop a new and improved core sampling assembly which would overcome the foregoing difficulties and others while providing better and more advantageous overall results.